There it is (full size after the jump), according to VGChartz.com. (Thanks to eagle-eyed reader LoadedStatement). One of the site's members did a SKU inquiry on the 360 and got that screen, which shows the $199 price taking effect Sept. 7. This apparently shows the SKU for the no-hard drive Arcade model. Other cuts are said to be coming for the Pro (60GB, $299) and Elite (120GB, $399), a development first reported by Ars Technica. VGChartz follows the pic with a detailed analysis of what the new price points could mean for Microsoft, and the timing behind the price change. An excerpt:

The scheduling of the drop is telling as well. It takes place 1 week after Square Enix's 'Infinite Undiscovery' and 2 weeks before Harmonix/EA's 'Rock Band 2' - both exclusive to the Xbox 360 platform at the time of release and pricedrop (obviously, Rock Band 2 will ship in November for the other platforms).